Depends on your pigs coat type WRT brushing - long haired do need daily brushing/combing, smooths just need the odd once over.
GP3 is a Rex (coarse wiry fur) he likes to store hay seeds in his fur 
Nails - when they look longish, if theres a bit of the opaque nail showing, usually there's a ridge , then the point. The opaque bit is the 'dead' bit. Easier with pink claws.
Baby pigs have needlesharp nails 
Check their eyes , ears and teeth too.
We bath them about 6 months, maybe more if they are going to the vet/on holiday
I use Xeno 450 (just treated GP3 yesterday)
If you do Spot Treat then wait a while before you bath them.
We dry them then put them in a box of hay to dry completely (though my DD has a really nice quiet hairdrier that they were ok with on the cooler setting. Keep your hand between the nozzle and the fur and keep it moving)
Check them all over when you cuddle them, they do get lumps and bumps, the quicker you find them the better. Might be a fatty nodule, might be a tick, might be an abscess.