Ok, this is what I am coming up with:
First, let's convert scoops to actual unit measurements. Litster scoop=2 tablespoons, Oqsy scoop=the 6 pound tub scoop 1/2 cup=8 tablespoons. Litsters pre-treat directions state 1 scoop=2 tablespoons. Oqsy 6 pound tub pre-treat state 1/4 scoop=2 tablespoons. That translates to the same mix at 1 cup per gallon, so that checks out, the same stuff, same strength.
-- Oxy Clean mixes range from 1/2 cup per gallon (weakest) to 1 cup per gallon (strongest) --
Litster used *2 scoops* (4 tablespoons in 8oz water=4 cups per 1 gallon). 4x the recommended MAX strength.
Oqsy used *4 scoops* (2 cups in 4 gallons=1/2 cup per 1 gallon). The recommended weakest mix ratio for Oxy Clean. 1x the weakest mix seems to work!
So we now know:
No sun=No deal
1x and 4x strengths do the job (maybe less will do it also)
THE BOTTOM LINE:
Recommended mix of the name brand "Oxy Clean" and water in sunlight for the first 6 hours or less gets rid of that yellow piss look. No caustic chemicals/mixing/equipment needed, it's the cheapest (costs pennies per gallon), least dangerous (it's a household fabric-safe cleaner), available everywhere, easiest (powder, water, container, sun), and over-dosing many times over doesn't seem to cause any problems/damage.
Share if you have experiences. Try to convert to standard units of measure to avoid some of the run around earlier in the thread (no more pooper-scooper). We still don't know the actual amount of solution needed, it seems much less than required to submerge the parts, so that's a moot issue. The various types of plastics may be affected differently as I had some keys that were considerably lightened.
I think we are at the point of confirming with a few more of these projects, that the 1/2 to 1 cup per gallon Oxy Clean mix in the sun is adequate to eliminate the yellow. Photos are always welcome.
