the major supermarkets do carry the dishwasher detergent so no problem to get them really..
have used a dishwasher for 8 years - mine is a borsch and i believe this is the best brand..tried using electrolux recently as its cheaper but not as good as borsch..

why dishwasher - very good if you have babies and small kids as the hot water will sterilize everything for one, secondly, great if you hate doing dishes..
so very convenient esp after dinner, lazy lah to have to do dishes..