Avoid having him around running water. You can do this and still bathe him.
1. Fill the pool without the dog near.
2. use a soapy wet rag to "pet" the dog into a lather
3. have dog play in his puppy pool
(you may need to do this a LOT to get him rinsed)
4. towel dry the dog & leash him because if you don't he will apply a nice doggy cologne like the one you just removed...
Good luck with this.
(also - get in the pool yourself - figure you will get wet and need your own "decontamination" procedure afterward. BUT you are making this fun, play anything but being squirted with a hose or doused with water)