When I was starting to wean my son off of the bottle when he was a year old, I tried almost every sippy cup out there, but he wouldn't do more than sip a little, then he was done with it. And then he also decided he was done with the bottle - no formula, no milk, nothing! That made it easier to wean him, but worse, because I thought, how am I going to get him to drink anything now?! I had tried the regular sippys with the valve, regular sippys without the valve, AND sippys with a straw. (I wasted a lot of money on sippys!) I figured out it was the diminished flow he didn't like. We had modified some standard sippy cups to increase the flow (hollowed out the spout), and he liked those ok. And then we either removed or tried to modify any no-spill valve in both tip-up sippys and the straw kind. He still didn't want them.
Luckily I soon came across some small juice-box sized sippy bottles at Wal-Mart (in the kitchen section), with a drinking spout and a straw that goes down. Those did the trick! Those little juice-box bottles were easy to carry and easy to drink from. They were cheap and broke easily, but at $1.44, big deal! Then we soon moved on to the Take-N-Toss cups with lids and straws, and now that's all he uses. It's more like a real cup, and he gets to control how much he takes in, whether it be a sip or a gulp, and I think that's what he likes. And now he can drink from any cup/straw combo, and we're working on going without the lid & straw on his cups.
I hope this helps, I know the frustration you're going through! Just keep trying - something WILL work!
(I have to add, as for cleaning the straws, if you have a dishwasher, just place the straws over the posts on the top rack! If you don't have a dishwasher, just soak the straws in hot soapy water for a bit and rinse well.)