I have had a few comments on my blog about treating sewing thread with mineral oil. Here are some more details:
Before machine quilting, I immersed my thread in mineral oil. I then dried off the spool with a paper towel so there would be no dripping or splashing. I have not had any problems with my machine or the fabric. I have only done this while machine quilting with my Juki sewing machine. My Juki is a basic single stitch machine, which calls for oiling every day with frequent use. I don't feel that the mineral oil will harm my machine.

I would certainly consult your owner's manual for your sewing machine. A lot of computerized sewing machines do not call for oiling (except for routine maintenance by a mechanic). 

I would like to know exactly what kind of oil "sewing machine oil" is. I have been doing some research on this and the information I've found is very vague. I did find one site that states sewing machine oil is a "light" detergent-free mineral oil. I would love to find a sewing machine mechanic to get his/her opinion, and all input is welcome.

Back to my sewing machine. I love tomatoes but I love quilting more. I am machine quilting a quilt for my friend Dee. It is a joy to be working on such a beautiful quilt and I am honored that she trusts me to quilt it for her. See pictures below.
I have worked up the nerve to try soaking my tread in mineral oil. I learned this in Sharon Schamber's class.
I filled a cup with human grade mineral oil and plopped my thread in for about a minute. Then I dried it off with a towel. It just slightly coats the thread, is a nice moisturizer for your hands and oils your sewing machine at the same time (apparently it is also good for occasional irregularity, which my sewing machine suffers on occasion). It does seem to strengthen your thread, as I had much less breakage while machine quilting.
I hope Dee doesn't mind that I tried this experiment while working on her quilt.