I had one of those left inside a softshell gator case for one of my other non-MM bass guitars. One day, I noticed that the chrome hardware on the bass had all rusted to a grungy looking brown.
It's very odd because at first I didn't believe the little packs could do that, but another bass I had at the time didn't rust at all and there was no pack in the case I left it in.
So I'm suggesting you keep it out of your case, unless you want a grungy look to your bass.
Desiccants are fine. They have a short life, usually less than 6 months (guitar case size) and will cause no danger to your axe, no matter how long they've been in there. The best storage for you axe is to hang it on a hanger (by the neck) out of sunlight and in an enviroment that does not experience a lot of temperature & humidity fluctuations.
They are great with a nice Merlot...But all joking aside, keep it in the case....The ones that come with EB/MM guitars and basses have instructions on how to re-activate them.
yes they do, but the one that came in mine didn't. how do you reactivate it? and once you do so, where inside do you put the pack, on the bass or what?