I sew on a piece of batting. Cotton or mostly cotton batting is pretty absorbent and I will also use a piece of batting or cotton swabs to wipe down whatever I can reach. I also leave the batting in the machine overnight, with presser foot down, to encourage oil to migrate down the shaft. Definitely sew a *lot* periodically throughout the day. Eventually you should see the thread become clean. Don't trust it right away though. Let the machine sit for awhile, and then sew again. You may need to sew on scraps every day for awhile before sewing your good things. It can take awhile for oil to disperse.