I have to do it the first time myself. I fired the engine up on the hard before I launchedthis summer though. I had the bucket in the cabin, disconnected the intake hose from the through hull and ran it into the bucket. It is good, in that it forces you to check that hose...mine was actually verging on failure with a split just above the nipple.
If you run from a bucket in the cockpit, which some people do to keep water out of the cabin, be careful. I was reading about this on ask all sailors and you must pull the hose out before you cut the engine or you risk getting water into your engine, potentially ruining it. This might only be a problem if you circulate the water back into the same bucket from the exhaust, but think it out and don't take chances. There is a risk that the water can back up thorugh the muffler into your exhaust valves.
The 2QM15 just doesn't pump enough water, in my experience, to drain a 5 gallon bucket all that quickly. I don't know if I will bother recirculating the antifreeze or if I will just hang a bucket under the exhaust and blow five gallons through the system. I haven't finished my research and I don't know how I'd adapt a hose to the exhaust to recirculate it, if I wanted to.
For oil and filter changes, bite the bullet and get a vacuum reservoir made for the job. I bought a small one for about $40 and it works well and was worth the investment. It holds about a gallon and I figure that I can use it for all my mowers, blowers, etc...too. Make sure you get some oil absorbant mats to catch any drips. I had to clean a ton of diesel from a leaky tank out of my bilge and after a ton of effort it is still marginal. I didn't want to pollute so I collected all the dirty bilge water in buckets that I now need to discard properly. The engine over bilge set up is an environmental problem destined to happen, so I added a bilge filter to my bilge pump near the outlet. I bought the proprietary $50 bilgeclean filter off ebay for $10 and the housing off ebay for $25. However, the whole set up is pretty reasonable at about $100 from the manufacturer. I put it in because congress hadn't passed the waiver on discharge from small boats yet, but I don't regret it because someone could still turn you in for a "sheen on the water." I also bought a reusable oil/fuel absorber to throw in the bilge and it works great. Another simple way to prevent discharge it to make sure you bilge pump switch is above your pump, that prevents the oil floating on the surface from being pumped out. Any way you slice it the design makes for a mess these days. In 1980's nobody cared I guess.
Anybody else got some tips for us?