Little Genie Bobbin Washers
 

I bought these but I really didn't see a difference in my stitches. I then searched online for comments and found out you have to take something out of the bobbin case (spring)for them to work. I don't think I have anything like that in my bobbin case. There are no instructions on the package. I read that machines already have built in an anti-backlash design. Could any of you advise me on this. Thanks a bunch!

Molly, I use these and they seem to help a bit for stitch consistency on machines like yours that don't have any kind of "springy thing" already in the bobbin case. It seems to make some improvement when I'm stitching at high speeds.
And, If you don't have anything inside your bobbin case, of course you don't need to take anything out. I have a few different machines, some I use the Little Gennie washers in, some I don't need to because the do have something already in the bobbin case to tension it and help it feed more consistently.

I won't totally swear by these things, but I do think they help a little.

The picture shows a bobbin case on the left that has an anti-backlash spring built in; on the right, a bobbin case without one that I use the Bobbin Genie in.

I think that the key word above is 'high speeds'. I first saw the inserts discussed in longarming where the machines zip along at top speed.

I have used them in my Bailey Home Quilter. Since I have used them I have had fewer bobbin problems.
My thinking is that they help the bobbin to spin faster and release the thread, so there is no drag on the thread.

My New Home machines have drop-in bobbins abd I have never even tried to use them as have no problems there.
I will always use them in my quilting machine.

I use this in my longarm to prevent backlash and it works great. (Backlash happens when you are quickly changing direction, the bobbin wants to keep spinning even though the machine has paused for a second, and you get a 'glob' of thread on the back of the quilt.) The trick is to put a tiny bit of oil in the bobbin case before you put the Bobbin Genie in. (I usually just wipe the back of the Genie along the neck of the oil bottle to get a small deposit of oil.) As long as I keep my Genie 'oiled' I don't have the backlash, if it gets dry, then the backlash starts again.

Not sure how these would work in a domestic sewing machine.

I use them sometimes in my Janome 4800 -for some threads they help. And I found the same with my Singer 201: they helped when using machine quilting thread (King Tut) but it did better without them when I had synthetic thread top and bottom.

Thanks to all of you for the info and pics. I have a7570 Pfaff DSM.