I would have used the dry even without floatant.
I use floatant to KEEP the fly floating. We can do without it too. A few good false casts will usually get a soaked fly to float a bit. Most good to fair quality dry flies will float quite well (for a while).
When we see rises, it doen't ALWAYS mean the trout are taking "dries" off the surface. They could be going for stuff just a fraction of an inche UNDER the surface. A "drowned" dry fly will often work well too.