I'm rebuilding an 02 TM 250 MX and what a nightmare it has been. The linkage bolts are so rusted and siezed I had to use a sawzall to cut thru them to remove the swingarm.The swingarm pivot bolt was deformed and siezed so badly I had to cut it out in pieces as well.The rear Ohlins shock shaft is bent as well. I'm starting to think some freestyle guy shot this bike a couple of storeys into the air, bailed off,the bike landed on it's back tire and was then parked to rust. 
The care or lack of care that some people have with their bikes astounds me. Sounds like the previous owner never took anything apart to lube it, then power washed out all the remaining grease!
If you don't know what you're doing with a power washer you can cause extreme damage.....
The reason so many people use them is that it makes cleaning their bikes very easy. But just because there is no chunky mud on your bike, does not mean that it's clean or even in good shape. Maintaining your bike will ensure that everything will work and come apart when needed. Also even more important to some, your bike will be worth more when you decide to sell it.
Sorry to hear about your struggles in getting the bike apart.
