Hey gang,
Bohemian Rhapsody has been wet about 6 times and actually washed about 3 times. It still looks great. The key is to use good quality fabric, a really good fusible, and then tight stitches. I use 2.0 x 2.0 length and width. If your machine allows for smaller increments, try 1.8 x 1.8 - that's what I most prefer. It is slow going with a double blanket stitch - not fast.
In the end I always always always say make a sample. Why not make a placemat size project with the exact fabrics, threads, fusible, etc. that you would use in your 'real' quilt. Then, just start putting it in with your laundry - marking it with a Sharpie tick mark for each washing. How many washings before it doesn't suit you. This really is the best way to determine usage. Even with all my experience, I'd rather not the the one to make that decision for you.