Pro® C-49 Heavy Duty Interior Cleaner 30:1 – How to Dilute Like a Pro (Beginner’s Guide)
May 28, 2026
If you just picked up a bottle of Heavy Duty Interior Cleaner (30:1) from Direct Detail Supply, you’re holding one of the most versatile and powerful professional interior cleaners available.
This guide makes it simple for beginners, with 30:1 as the standard starting point. Only go stronger when needed for tougher stains.
Easy 32oz Spray Bottle Dilution Guide
|
Job / Stain Type
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Dilution Ratio
|
Water : Cleaner
|
32oz Bottle
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When to Use
|
|---|---|---|---|---|
|
Everyday interior cleaning
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30:1
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30 : 1
|
1 oz cleaner + 31 oz water
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Most seats, carpets, door panels, plastics, light dust
|
|
Greasy doors, steering wheel, armrests
|
20:1
|
20 : 1
|
1.6 oz cleaner + 30.4 oz water
|
Heavy hand oils & grease buildup
|
|
Sticky kid snacks & sugary spills
|
15:1
|
15 : 1
|
2.1 oz cleaner + 29.9 oz water
|
Juice, candy, chocolate, soda messes
|
|
Old dried food & crusty spills
|
10:1
|
10 : 1
|
3.2 oz cleaner + 28.8 oz water
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Dried milk, fast food, spaghetti, etc.
|
|
Dog poop, vomit, or heavy organic stains
|
8:1
|
8 : 1
|
4 oz cleaner + 28 oz water
|
Serious accidents + odor control
|
|
Extreme grease / bad spills
|
5:1
|
5 : 1
|
6.4 oz cleaner + 25.6 oz water
|
Very heavy contamination (test first)
|
Always begin with 30:1 (1 oz cleaner + 31 oz water in a 32oz bottle). This is strong enough for the majority of interior cleaning jobs. Only make it stronger if the stain remains after the first application.
How to Mix in a 32oz Bottle
For most small jobs, simply add 1 oz of cleaner after filling the 32oz bottle with water.
- Fill the bottle with the proper amount of water first.
- Add the measured amount of Heavy Duty Interior Cleaner.
- Stir gently with a clean stick or swirl the bottle slowly to mix.
Do not shake the bottle — shaking creates excess foam. - Let it settle for a minute before use.
- Label the bottle clearly with the dilution ratio, date mixed, and “Refer to SDS” for safety information.
For most small jobs, simply add 1 oz of cleaner after filling the 32oz bottle with water.
Real-World Recommendations
- Start at 30:1 — Perfect for regular maintenance and most stains.
- Move to 20:1 or 15:1 for greasy or sticky messes.
- Use 8:1 or 5:1 only for the worst cases (dog poop, old dried food) and always test in a hidden area first.
- Always test in an inconspicuous area first.
- Be especially careful with leather — previously dyed or older leather seats can have color removed or become discolored with stronger dilutions. For leather seats, we recommend using Pro Leather Cleaner instead.
- Never use full strength on vinyl, leather, or delicate surfaces.
- Let the solution dwell 30–60 seconds on stubborn stains.
- Agitate the area with an S.M. Arnold Nylon brush (for vinyl and cloth seats) or a carpet brush (depending on material) to work the cleaner deep into the fibers.
- Scrub gently, then extract thoroughly with a Mytee® extractor whenever possible.
- Don’t let the cleaner dry on the surface.
- Work in sections and ensure good ventilation with stronger dilutions.
Important Disclaimer:
Heavy Duty Interior Cleaner is a professional-strength concentrate. It is a powerful product that must be respected and used responsibly. Improper dilution or application can damage surfaces, especially leather, vinyl, or delicate fabrics. Always follow the recommended dilution ratios, test first, and refer to the SDS. Direct Detail Supply is not liable for damage resulting from misuse of this product.
Heavy Duty Interior Cleaner is a professional-strength concentrate. It is a powerful product that must be respected and used responsibly. Improper dilution or application can damage surfaces, especially leather, vinyl, or delicate fabrics. Always follow the recommended dilution ratios, test first, and refer to the SDS. Direct Detail Supply is not liable for damage resulting from misuse of this product.
Ready to tackle your interior?
Shop Heavy Duty Interior Cleaner 30:1 at Direct Detail Supply offers local Bay Area delivery to new clients What’s the worst interior mess you’ve had to clean? Share in the comments!
