I haven't used Muse, but based on my experience with Bimix, I suggest this:
Before inserting the Muse, put some constriction around the base of your penis -- the ring that comes with a VED or a few rubber bands doubled over. Then do the insertion and whatever massage you need. After a few minutes, remove the constriction -- I now use two minutes with Bimix.
My theory is that this stops the drugs escaping too quickly and forces them to hang around to do some good. I'm not completely convinced, but whatever the reason, it makes a big difference to me. I don't know whether it will help you with the Muse, but it's maybe worth a try.