I tried it, although by mistake I added some vinegar solution to the THH HCL to dissolve it. Old habit

After it had all dissolved, I added it to a saturated salt solution. Instantly, whitish precipitate started forming. So, yes, it does seem to work with THH.

Another point to make, after dissolving the THH HCL in a very small amount of water/vinegar, I could see no colour change as with harmine and harmaline. It is most likely a colourless liquid.