I'm with gerryb...I use an iron-on tear away...but, be careful...depending upon the density of your design, it may not be enough. I have had really dense designs cut through the stabilizer and then I have had the fleece get sucked down into he bobbin case...can't remove the hoop and have to carefully cut it off...then I find lots of the upper thread entangled in the bobbin case...really a bummer! I think it's because of the stretchy fleece and lack of support from the punctured stabilizer. With dense designs, I slide another piece of tear away under the hoop and then embroider the design.
I've been using an iron on tear away on some projects & like it! It's like butcher paper, irons on yet tears off very easily with no residue. By ironing it on, the fabric doesn't stretch. I THINK Floriani may make it, but I have been using Fuse 'N Tear by Inspira. May want to give that a try, but be sure & use the topper. I like the Sulky as it will tear away easily so I don't have to wet the project...I'm usually getting it done right before it's needed!! NOTE: a friend uses it, but hoops the stabilizer, then puts her material, like thick things, on it & THEN irons it on while in the hoop so you don't have to hoop a thick material.
I use a light weight tear-away and wss on top...keeps stitches on top of fibers. It usually tears off well on both sides......I do not hoop either. I hoop stabilizer and then tack down fleece and wss at the same time. Great results so far.....Good luck....
I use either lightweight tearaway or iron-on light weight, then take off any excess. Works pretty good. You might also want to try and hoop the stablizer only and lay your fleece on top. Some machines have a 'frame' stitch to hold it down or you can use a small amount of the spray adhesive. (I don't like the spray) or even pin it at the very top edge and bottom edge. Either way one of these should work well for you. Depends on your preference. Good luck and have fun. (p.s. I never use washaway on fleece or flannel, kinda yucky :-)