Hotpoint WF541P Bad smell and door seal turning black

put in a cup of strong bleach on final rince

You need to remove old door gasket and fit a new one

I use "Affresh" every couple of weeks to keep the washer smelling good. Here is the product to order.

get some descaler part No C00090908 that should sort the smell as for the seal you will better off replacing it

Hi.
The smell will be coming from inside the drum as you summised.
It is probably caused by the drain in need of cleaning, or more likely a build up of dirt and scum on the door seal cased by doing too many low temperature washes.
Check the seal carefully and if it is stained black, then the only real solution is to replace the seal, and do more high temperature washes

Water maybe stale and mold maybe building inside the seal for the door. Use bleach water and a washrag and clean the seal and run a just bleach and soap load through the washer on its hottest setting to kill anything you can reach or wipe down. Do this whenever you feel its not clean to your standards.

Is the hole, or a tear? If its a hole, that's the normal hole to get the excess water out of the door gasket. If there is a tear, you'll need to replace the door gasket. The smell you get, is due to not leaving the door open, you'll need to leave this, and the dispencer open all the time, when your not washing. The unit needs to vent, in order not to have build-up of mildew/mold.

run your washer once on a qick cycle with bleach and afterwards and after every load leave the door open. the smell is mildew which is common with all front loaders. if you leave the door open the moisture will dry and your odor problem will go away.

It probably is related to your drain outlet, depending on the set-up, I would suggest you remove drain hose and clean the place where the drain hose enters the drain system, if possible, clean all associated pipework
Please rate my solution.
Thanks.

ebay sell all kinds of bearing kits. about £10 usually.