Hi I will play soon in an Alice In Chains umplugged tribute band and I don't want to take an acoustic bass!
I don't like play acoustic too!
I don''t wanna spend for an acoustic one!
so let me ask for some good ideas to reach the nearest-to-Inez sound I can!
The bass I have are a G&L L-2500 and a Laurus quasar fretless, someone know it? Here is a photo of a Laurus quasar.... it's a five string fretless because I don't have any photos of my 4-strings fretless!

I've found muting the strings with my palm and plucking with my thumb gives me an acoustic, double-bass sound. Other than that, if your bass looks like it's wood, and you play sitting down, you should look 'unplugged.'