The use of lye as a paint stripper has been discussed here, so this post is not too far OT.
Essential Depot has lye on sale for $1.99/ 2 lb bottle (through Friday). That is a great price. But the shipping is not so great: $19 for 5 bottles (10 lbs). But there is a 20% off shipping promo ("SHIP20"). Bottom line: $25 for 10 lbs - can't be beat.