capnjonny 

I have been using Clean strip on my frames. if I applied it normally and waited 30 min it often wouldn't do much to soften or lift the paint. Lately I have been putting multiple coats of stripper on the frame then covering it with aluminum foil . This can cover the bottom bracket and head tube tightly because the aluminum foil is very moldable. After sealing the frame in tin foil I let it sit for a few hours to over night . when the tinfoil is removed the paint under it is much softer and easier to remove.

Note that I also remove most of the paint by scraping with one of the little disposable sliding blade knives - the kind where you can break off the tip of the blade to ecpose another sharp end. Using this I can strip most of the paint off a frame in 2-3 hours.

finally, I have a small sand blast rig that I use to remove the paint from the lugs and also any serious rust. After treating with the paint remover the paint easily comes off with the sand blaster. All told I probably spend 6 hrs to completely remove rust and paint.