Back in May 2009 - back before I started with traditional wetshaving - I picked up a bottle of peat shampoo as a souvenir while I was in Finland.
Peat shampoo and soap has allegedly antibacterial properties, and is claimed to be good for all sorts of problems with your scalp. While I can't comment on the former, I know that it helps with dandruff and the soreness you get after a sunburn...
The smell is not everyone's cup of tea - it smells of old pinewood and bogs - it's a scent I rather like adn it pares well with the TSN Brutalt Bra LE shaving soap.
Peat shampoo seems to be something of a Finnish thing - at least the ones I can find online all seems to be made in the land of a thousand lakes - but if you got scalp troubles or a sunburn, you could do a lot worse than giving peat shampoo a try.