Don't use any sealant
It's in my book, page 20, last complete paragraph: "To put the new hose onto fittings, heat the hose with a blow dryer (use a heat gun only if you really know what you’re doing with one) to soften it. Be careful, and be patientl! You only want to soften the hose enough to slide it onto a fitting; overheating hose can damage it, causing collapse or tearing. Smear a little dish soap (or even better, K-Y surgical jelly) on the inside of the hose and the outside of the fitting to lubricate the connection. Don’t use Vaseline or any grease...and don’t use ANY cement or sealant...only Teflon tape on the threaded end of fittings. Double clamp all the hose connections."Flushing the toilet in the dry mode should completely empty the bowl. Any manual marine toilet that's working anywhere near the way it's supposed to can move bowl contents (waste and/or flush water) at least 6' in the dry mode, even uphill. If it doesn't, you aren't pumping long enough to move the water over the top of any uphill section of hose from the toilet...it's running back downhill into the bowl. A new joker valve (included in the rebuild kit) will let you get away with not pumping long enough for a short time, but will not prevent slow seepage of any water left in the head discharge hose back into the bowl for very long. If it's uphill all the way to your tank, and if your tank is more than 6' from the toilet, put a loop--doesn't have to be a vented loop, just an arch--in the head discharge line that will allow you to pump only long enough to move waste/flush water over the top of it in the dry mode. The loop will also help to prevent waste in the tank from running back toward the toilet when you're heeled.