I glue baste all the time and my machines have had no ill effects from it. I've never had a problem. I do use a thin stream and wait for it to dry completely before I use my machine. You don't need to use very much and it doesn't have to be spread all over. After all, when you baste with thread or pins you don't have every surface covered. Glue is the same concept. For a full size quilt I use about 1 regular size bottle of glue full strength. There are many discussion on glue basting on Quilting Board. If you use the search function you'll find a lot of information.
I have never had anyone tell me it would ruin my machine but a friend had someone at a quilt shop tell her that. I'm not sure where people are getting their information about ruining a machine. It doesn't seem to be from personal experience. I couldn't find any residue on my needle whenever I sew over dried glue. To wash it out I did find I needed warm water. I usually wash with cold water and that didn't seem to dissolve it all.
The last time I saw washable glue at JoAnn's it was way more expensive that I've seen it other places. You can generally find it for around $1.00 a bottle or less. Back to school sales are great but if you want it sooner I've seen it at Dollar General (Elmer's brand) for $1.00 and Walmart and other discount stores have it for around that as well. Don't pay JoAnn's prices for it.