Not an Almand owner but I have replaced hoses/toilet in two boats now.
Discharge hose is probably 1 1/2", intake hose 3/4".
I've used this hose
on both heads I've worked on. It is very easy to work with since it is so flexible.
To limit the "spillage" I use my vacuum can (for changing oil) to suck remainingn fluid from hoses before I remove them. As soon as I pull a hose end off I cover it with plastic and some tape to seal it. So far I haven't spilled anything when changing hoses.
Not the favorite boat project but certainly improves the ambiance if you're having odor issues.