The strongest non-prescription numbing substance you can apply around a scrape, wound, or burn is Lidocaine. You can find 2% lotion in expensive little tubes (8 per pack) for burns called Activ BurnStuff at most drugstores. You can also get topical anesthetic pads with 2.5% Lidocaine from Chinooks. Good for bee-stings, too.

Activ Burnstuff
8 tubes
Item # F1-750-08001-01
$4.50
Activ USA

Lidocaine First Aid Lotion
Item #01041
$5
Chinook Medical Gear
800-766-1365
970-375-1241