I don't recommend the nuts/bolts/bb's method, just because it an be a real pain to get them back out of honda gas tanks. I use a different method:Start with a tank with everything off/out of it. Strainers, fuel pumps, whatever. Nothing but tank metal left. Buy a couple of rubber caps to plug off the vent line, and maybe a big cork for the fuel cap hole.Go buy a gallon jug of muriatic acid from the pool store, and a bottle of naval jelly (maybe 8 oz or so).Shake hell out of the tank upside down to get out as much grit and loose junk as possible out of the gas cap. Expect a workout on a honda tank.Now, in a plastic bucket, pour naval jelly and a gallon of water in and mix.get it nice and smooth.Do whatever you gotta to prevent any muriatic acid (HCL) from getting on the paint in this next step. I use a paper funnel and a measuring cup.Plug tank up, and fill about 2/3's with water from hose. Slowly add 4-5 cups of muriatic acid. SLOWLY. DO NOT PUT ACID IN TANK FIRST. WATER FIRST.Plug up gas cap, then slosh mixture around inside tank for a couple of minutes. Repeat every five minutes for about half an hour.Turn on a garden hose, and find a good place to dump the tank. the mix isn't all that dangerous, but it will discolor concrete. flood the outside of the tank, remove cap, and dump tank while flooding paint area and anything acid might touch with lots of water. Aim the hose at the mix you dumped out and dilute the hell out of it. acid dilutes very fast and well.Now, before inside of tank can dry, pour the naval jelly mixture into tank. Slosh it around and rotate tank in all directions to be sure inside is completely coated with the mix. Do this 4 or 5 times, then dump out the mix in the same manner as before, with a hose and tons of water. Set the tank upright and let dry 20 minutes. Flip the tank, let dry 20 minutes. Then, rinse insides with water.Remove all plugs, and let tank dry in a nice warm place ( I always set tank in sun) for several days. Tank needs to be bone dry before you put gas back in it.Thats the process. The muriatic (hydrochloric) acid will dissolve the rust and any remaining varnish/old fuel right out of the tank, and usually leaves it nice and clean. Naval jelly is basically phosphoric acid. It will leave a long-lasting phosphate coating inside the tank that prevents the flash rusting that WILL happen after you clean one out.Works for me. Good luck!