Sound like you soaked the decals for too long and washed off the adhesive.
Go to the grocery store and buy a bottle of Future Floor Finish.
Remove the decal if you can and dip the back into a bowl of Future and apply. Use brush to paint the Future under the decal if they are partially stuck on.
Apply more Future with a wide CLEAN brush over the top of the decal. Then flood coat with even more Future.