I have had good luck with the following products for getting that sticky
crudy stuff off:
Simple Green and Simple Green Carpet cleaner, the latter seems very good at
pulling stuff off without being very harsh or smelly.
Also Prestone carpet and upolstry cleaner, comes in a spray can with a
scrub brush attached.  Was as simple as spray, scrub, wait 5 minutes, wipe up.

Bad experiances with Purple Power and several other of the strong alkaline
cleaners.  Discolored paint and seems to attack various plastics and
corrodes any aluminum.

Hope that helps,
Dave K.