Cutting the hair short can reduce that time. You shouldn't need to bathe your guinea pig. If your cavy gets dirty, try to spot-clean with a damp, soapy washcloth. Guineas don't deal well with cold and drafts, so keep it warm while the fur dries. One of the joys of keeping a guinea pig as a pet is the sounds they make.
Guineas do chatter, squeal and grunt - quite a difference from quieter rabbits and rodents.
Content guinea pigs, also called cavies, will make low-pitched versions of those sounds, as well as cooing noises. Generally, you'll hear these when you're cuddling or petting your guinea. Squeals usually greet food or treats as well. At least you will know that your guinea pig is appreciative of the meal. Cavies love attention and they like to be with other guinea pigs.