I use paint thinner. put a gallon or two in and take a bath with a tire brush wash it out with the garden hose..

Yeah, put in five or ten gallons of water with Simple Green. Take it for a run. Let it slosh for an hour or so. Does real well.

Simple Green and most other cleaners don't work nearly as well at 100% strength. No "carrier" to suspend the emulsified grease in.

Super Clean is hard on bare aluminum.

Superclean here too.

Buck

Just use the standard purple stuff at Autozone or the Castrol. Very strong stuff as you can feel when your hands burn. I generally just throw some of the concentrate in the bilge, add some water and drive around on the trailer or water for a while then flush it.
Spotless for $4....
Self cleaning

If you fill the bilge with soapy water and drive around on the trailer, be careful. Don't fill it real full and then trailer down hills with stop signs at the bottom.

BTW, anyone know a good way to get soapy oily residue out of the cabin carpeting?

I only drive up hill

good idea guys....I'll throw the ole purple stuff in w/ water...go fill her up w/gas and she should be spotless by the time I get back.

OK guys... don't laugh... but I've found something that works better than Castrol superclean... doesn't burn your eyes as much.. costs less... and is easy to find... at least for me... it is a Laundry pre-treater... the name of the stuff is "Soilove".... I can buy it for 99 cents for a pint... when you compare it in price to Superclean it's about the same.. $8.00 per gallon. I put it in a spray bottle.. spritz down everything and let it sit for about 10 minutes.. brush....spritz again... wait another 10 minutes..brush... then hit it with a hose... sparkling clean. I even use it to clean engines after they have been removed from cars.

Before....

after using only Soilove and water....