Ours is only 1 1/2 gal. with heater, we've tried purple power , mean green. an totally awesome. All at different temps. We've tried 70% alcohol with no heat. Mineral spirits ( varsol) Our best results are with heated diesel fuel. Bigger parts nothing beats a heated pressure washer first. If I'm doing the small carbs. on outboards. 2-15 up. , we have the 1 gal. can of gunk carb. cleaner ( especially Honda, tohatsu, yammy's, merc. an suzuki) soak for 4 hrs. no plastic or rubber. If I'm doing 3 two barrels carbs. On the 150-250 hp. Merc. Jonnyrudes and old Suzuki. We have a 5 gal. Can of gunk carb. Cleaner .
If I'm doing the composite carbs. off the jonnyrudes. Use the heated diesel fuel with sonic. Now back in the day , each mechanic had a varsol vat in there work bay , 8 gals. Vat was split in half . 1 half had a basket and a metal tube drilled with small holes and a regulator attached , we hook shop air to and used air agitation. That tells my age:biggrin