The cautionary note is good Ignatz. I can see that just leaving a razor to lie on the bottom of a pan of hot water would expose it to the higher heat from the heat source at the bottom of the pan.

The 100 C/212 F temperature of a bath where the blade was suspended would not be enough by itself.

I, and some others, routinely heat treat steels using a molten salt bath. The quench is often as high as 150+C/300+F depending on the steel and the requirements of the tool. But the blades are suspended and removed from potential contact with the heat source. The legendary lead baths at Thiers and Dovo would be similar in principle.