I haven't used this stuff, but guitars are definitely low voltage so from that standpoint it would probably be OK. However, I have heard that most of cheap glues are carbon based, and could add resistance to the circuit. So I would be afraid that it might change the sound a little. Also, I have heard that some are quite viscous so you would need to be very careful that it does not run somewhere that you don't want it. I have no idea how long it lasts, but some glues break down over time, whereas solder connections are virtually forever. I think I'd be inclined to stick with solder.

What it might be good for is to use as shielding as an alternative to copper or aluminum tape. Again, judging by what I have read, wire glue sounds similar to shielding paint in composition. I haven't used that either, but a lot of high end mfgs shield with it.