I know I was about to sleep in a cheap place without an aircon. The toilet without the flush was no problem for me (bucket with water was provided). Dirty pillows? I can ask for new ones (they were mouldy I think). Cold shower is fine as well, after all we tried to safe some money. The sheets were washed, but had some stains, not to bad, we had that in more expensive places as well, can happen at home too.
BUT it was impossible for me to sleep. The mattress was so old, that you eventually had to meet in the middle of the bed, sleeping in a valley of a mattress. We checked out a day earlier and got a hotel, a nice one. If you are looking to safe some money, Koh Tao is not the place for it.