Peggy, I'be been reading your posts about urine crystal buildup in head hoses and want to be preventative. I have a manual flush head on a H380 and use fresh water to flush (using shower head to put water in) unless we are cruising then we use salt water until we return. This has greatly reduced the horrible rotten egg smell we used to get from the head in take hose. 
)))) Now on to keep the outgoing hose clean. I make sure I use enough water to get the waste back 8 feet to the holding tank, but how do I get the vinegar into the hose, letting it sit and then get a good flush? Thanks for all you do here, I thought your response on vacuflush heads yesterday was a very professional, well thought out comparison without favoritism. Extactly what we've come to expect from you. Well done. Bob Knott H380
)))) Now on to keep the outgoing hose clean. I make sure I use enough water to get the waste back 8 feet to the holding tank, but how do I get the vinegar into the hose, letting it sit and then get a good flush? Thanks for all you do here, I thought your response on vacuflush heads yesterday was a very professional, well thought out comparison without favoritism. Extactly what we've come to expect from you. Well done. Bob Knott H380