Mark & Debbie Mueller
I opted for the low tech approach. First I installed a small filter prior to the refrigeration raw water pump to filter out the smaller unwanted bits that escape the main strainer or grow in the supply hose. When cleaning the main strainer turn off the intake valve then remove the bowl of the small strainer then open the lid on the main strainer. The small strainer is below the level of the discharge of the main intake so the water level drops and the main strainer can be removed without critters or junk getting out of the main strainer. However, in my case I have a course bristle brush on the end of a pole that I push down through the strainer, open the intake valve, push the brush down to clear the bottom of the boat to assist the exit of any remaining coarse debris, hold the strainer in place with one hand withdrawing the brush quickly so it clears the valve then close the intake valve. With a little practice this can be done without water overflowing the main strainer. Then remove the plastic insert and clean normally. No hazmat suit necessary.
This method works very well when the strainer in the intake becomes clogged. The attached show the results of a jellyfish bloom. We had to clean the main strainer every 4 - 12 hours this summer. My wife had to do it when I had to be off the boat - the methodology worked but she ran the A/C for shorter intervals.
Not wanting bilge spray blow back I flush with a garden hose on an irregular basis but add Unique Natural Products Marine Digest-It Holding Tank Treatment. It is a blend of bacteria and enzymes that is safe for plastics and metals. I believe its byproducts are CO2 & water. A couple of tablespoons every 2 - 3 weeks seems to work pretty well - no smells and a fairly clean bilge.
Brass Ring A54