This stuff is awesome.
If the insides of your sewing machines tend to look like mine (this was my serger after one apron!), buy a can of compressed air--you can find it in the computer/electronics department. A few shots inside, and all that excess lint and thread that's clogging your machine will be gone.
And apparently my two small children and I look like crazy glue huffers to the check out guy at Walmart, because I got carded buying this can. Ha!