If you are using washing powder, just use a small amount, well dispersed in tepid water, and rinse thoroughly. It doesn’t really matter what sort of detergent you use, just so long as you don’t use too much. I do know people who use block or soap bars just applied on the ‘pongy places’ - feet & crotch!

Whereabouts are you? Our local supermarkets, now the hysteria has calmed down, have plenty of stock.

A small amount of baby shampoo or wash might work

I've used both liquid handsoap and shampoo/shower gel. But bar soap should also work...

Also have you ever tried soapnuts? I use them for my usual laundry and they are also very good for handwashing. A fivehundred gram bag last months and months livewelluk.co.uk/products/l...

Have never heard of soapnuts before....! Just had a look and they seem a good idea. Thank you

You can use a little washing up liquid but really if the water is just hot enough that alone should be enough to get them clean.