Non-Bitcoin Uses for Old ASIC Miners? Can I use an old ASIC Bitcoin miner for other applications? For example, quickly reindexing the blockchain on my computer? Or quickly hashing every file on my hard-drive?

(I really wonder if the hard-drive could even supply the data to the miner fast enough, and the computer's CPU would probably have to be involved, translating the data for the miner, so that would be a bottleneck…)

(Note: My question differs from "Reusability of ASIC miners" because I am only asking about hashing-specific applications, not whether ASICs can do other mathematical operations.)
Anything that makes ASICs suitable for applications other than the Specific Application the Integrated Circuit was designed for would probably slow it down or make it more power hungry or expensive.

One side effect they do have (along with anything else electronic) is that they convert 100% of the electricity into heat. So you could use them instead of an electric heater.

Note that heat pumps are actually more efficient, so it's not optimal. And in a lot of countries burning natural gas for heating is cheaper too.