Standard hose (ie. new spare one); nylon to metal at supply side, nylon to nylon at washing machine side. PTFE thread tape needed?
A: Absolutely not…more harm than good.
B: Won’t do any damage.
C: Yes, definitely.

Wont do any harm, but shouldn’t need it as there should be a flat rubber washer inside the head of the hose that will seal against the washing machine when tightned up

What jim25 said. The seal should be made by the rubber washer so if water is getting as far as the threads then it is already going wrong 😀

Yeah, buying a pack of those too. There’s been a very slow leak-by at the supply side and the hose connection at that side is full of crud & scale. There’s a screwfix two minutes away so just getting a new hose to save faffage. I’ll pick up some tape while I’m there.

@GrahamS, yes, I understand what you mean. When I took a close look at the connection to the supply, it didn’t look entirely square…only very very slightly. There’s PTFE tape on that one, so I assume it held fine when it was first connected but gave way eventually.

Make sure there is enough slack in the hose that the connections don’t get jiggled about while the machine is on spin. That can cause them to wear and weep a bit.

+1 – I had hoses which were just about long enough. Getting longer ones solved lots of problems.