Cleaning an Omni 4000

The simple, green, answer is: Yes.

Simple Green by itself will not harm rubber (natural or synthetic) for short term washing or immersion (don't leave it overnight!)

BUT: Simple Green plus vibration from the ultrasonic cleaner will dissolve/erode/otherwise damage many synthetic and natural rubbers. If the paint won't come off the seal and o-rings with simple washing or scrubbing with a soft toothbrush, you can put them in the ultrasonic for a few minutes, but I wouldn't leave them for longer unless you have replacements handy.

Be sure to relubricate the o-rings and seals with silicone grease or spray (Regdab Needle Juice will do.) after you clean them.

Not really slamming Micromark, but their prices are usually at the high end of the range. OTOH, you can't beat their service, regardless of the stick you use.

Ross, quick question about Simple Green... will it eat the rubber seals or is it the bubbles from the sonic cleaner that will do those in? I don't have a sonic cleaner but Micromark has one a decent price...

Gentlemen, thanks for your input! 

Also, if you have a small ultrasonic cleaner, you can do a complete tear-down and put the parts in that with some Simple Green. Don't clean the o-rings or seals that way, though.

Be sure you get the paint out of the air inlet valve!