Portable bottle warmer

We use a milk warmer instead of bottle warmer. It’s portable and works well. Heats to 37°C in like 2 mins. We’ve been using it since she was 4 weeks old and she’s now 13 months

Cordless Portable Bottle Warmer,... https://www.amazon.co.uk/dp/B0DXV3C4ZL?ref=ppx_pop_mob_ap_share

Do you have to keep cleaning it every time you heat up milk?

It's expensive but I use the Baby Brezza portable one. I was hesitant because of the price but it's the only one I've found that I can heat the breastmilk storage bag in so it saves sterilising every time we use it. If we want less milk then we just use it as normal and sterilise but if using a whole bag we don't need to sterilise every time we use it

We found this one online and it works well. Great price. We've had it for almost a year.
https://a.co/d/0gNPpBJL