Have you tried that product called Simple Green? It is non toxic and you can get it in a spray bottle or in a concentrated form that you mix with water. You spray it on, wipe with a cloth and hose it off, then dry your bike. But if you have serious, serious grease and oil problems, use Gunk. It is an aerosol degreaser that you spray on and wash off, but it is toxic and if you let it sit for a time it can be bad on rubber parts. I'd try Simple Green first, Gunk only if you are careful. Both can be found every where.