Fels Naptha is the best stain treatment and it is cheap. Check out this post on how it gets almost anything out!
Directions for how to get stains out of concrete. Can't wait to try this on all of Matt's old oil stains in the driveway!
If your kids play travel baseball or softball you know about "red dirt". This stuff will get set in stains out. Soak overnight in HOT water... red dirt stains... gone Super Iron Out Rust Stain Remover - Best Price
Multi-Purpose Problem Solver: WD-40 WD-40, cleans, lubricates and protects against corrosion. It also removes grease, gum, dirt, adhesives, & scuff marks. Wonder How to Remove Grease & Protect Against Corrosion? WD-40 is the Answer! Want to lubricate sticky drawers? Clean crayon from walls? Remove glue and adhesives? WD-40 is the Answer. Learn thousands of new uses, from protecting ski bindings from corrosion to removing gum from hair and carpet, by browsing WD-40's 2000+ Uses List.