my DD had really bad thrush for like 2 weeks before we got her on daktozin, it was all bumpy and yuck and gross and blistered. We used daktozin for a few days and it healed up but we kept using it for about 1-2 weeks after at every change to make sure every trace of the thrush was gone.
Her bum now is lovely and smooth and clear, so I wouldn't worry just yet. DD's was HORRID and is ok now.