a cloth, and string cleaner. both can be purchased at your local music store.
The Gear:

Custom Strat
Mesa Boogie Stiletto Ace
Fulltone OCD
Electro Harmonix Small Clone Chorus
Dunlop Crybaby Classic
MXR EVH-117 Flanger
Fulltone Soul Bender
just take a towel and wipe em down after playing... if even that. if they're really dirty just change em