PB Blaster beats the torch on a seized caliper bolt 9 times out of 10

My 2004 F-150 ate rear pads down to the rivets last month and the lower caliper bolt on the driver side was welded on there like it was part of the bracket. I hit it with the propane torch for like 15 minutes, tried a breaker bar, even swore at it in Spanish which normally works. Then my neighbor Bob comes over, and he's this old guy who drove a cement truck for 30 years, and he says "try the kroil and a cold chisel, not the flame." I thought he was nuts but I let it cool, soaked it in PB for an hour, tapped the bolt head with a chisel to break the rust bond, and it spun out with a regular ratchet like it was butter. The heat was probably expanding the bolt in the bore and making it worse, which sounds backwards but that's what happened. Anyone else found that cooling and shocking a bolt works better than heat on these rusty northern trucks?