Been there with a 99 Civic, same exact deal. Dropped the tank in my garage and it was full of rust flakes and brown sludge that looked like coffee grounds. I tried the whole clean and seal kit thing (the pour in stuff you slosh around) and it lasted maybe 6 months before the flakes came back and killed another strainer. The real fix that actually held up was swapping in a used tank from a junkyard car for $60, plus a new strainer sock and fuel filter while I was in there. If you go the cleaning route you have to get every last bit out and replace the strainer and filter at the same time, otherwise you're just feeding the same junk back through. Also check your fuel filter under the hood if yours has one, mine was packed with the same rust. Three years later and the junkyard tank is still going strong, so that's the route I'd take again.