BoozeKashi: I have a gas oven that poorly regulates temps near 100C, so I have a developed a different approach. I put my finished pieces into a pot of water and boil them for 5 or 10 minutes. For smaller parts, I have even tried using a coffee cup full of water in a microwave oven.

Boiling water has a fixed upper temperature of ~100C. I believe that the steam above the water in a covered pot could be higher than 100C, but that has not caused me any issues so far. The water supports / floats the piece, so any warping at elevated temperatures that might be caused by weight stress during annealing is eliminated. IMO, the parts do seem to warp less often than when I use an oven based annealing process. This does not mean things cannot warp, just that they would do so for different reasons. I've also read that the parts may shrink slightly as the result of being heat annealed. I've not made the measurements to check, but after hundreds of parts it has not caused me any problems (so far).

I wrote and asked Makergeeks for their opinion of my "boiling" approach to annealing and they endorsed it, even posted my enquiry email on their website. I've seen a video that someone else had created that applied this "boiling in water" approach with apparently excellent results.