Don't smell your bottle

I rinse mine out as quickly as I can then fill it with cold water to the top (including the lid) to help break down any stubborn bits of Huel left. Then after I few ours, I stick it in the dishwasher. After cleaning, I rinse it all out.
Probably a little excessive but it doesn’t take much and it makes sure it’s sufficiently clean

Ideally you should put water in the shaker, shake it and empty it straight after drinking. Then it’s a doddle to clean when you get around to it.

But that’s not always convenient. In that case, after drinking, close the cap. This stops the remnants drying out and becoming hard to clean. I’ve left a shaker for 12 hours like this and while I didn’t sniff it before washing it, there was no smell after washing.

One thing that might matter: I keep my Huel in the fridge until I’m ready to drink it. It never sits around at room temp so there’s no opportunity for evil spirits to infest it until the shaker is empty.

I’m the same. After drinking rinse immediately with cold water, & immediately make another one, stick it in the fridge til its due.

Wash with hot water and soap every few days, no more. No stink.

I stopped using plastic shakers long ago for this reason, only stainless steel. Currently using beyond shaker and really happy with it. A few years ago there was a Huel one, no idea why they discontinued it.

Huel has never had a stainless steel shaker. First they used an off the shelf one. Then they made their own one (current model). They did have a steel water bottle but no good for Huel.

I can confirm, that I wouldn’t recommend using a stainless steel bottle for Huel, as a newbie back in the day I used our stainless steel water bottle to make Huel… it did not go well…