I've found that liquid detergents give the best results in my AEG lavamat washer dryer. These work well when I want to do a normal wash, I just pour the liquid into the supplied ball, pop it in the drum and off it goes.
When I want to use a pre-wash programme however, I have a problem.
The washing machine detergent drawer is not designed to hold liquid detergent, only powder, so I can put liquid detergent in the ball for the pre-wash part of the programme, but then have to use powder for the main wash.
Some AEG lavamat washer dryers have a detergent tray which comes with a flip over divider (you can buy replacements or print your own) but mine does not.
I have played with using sellotape (Scotch tape) and offcuts of plastic to seal off one end of the powder drawer so I can add liquid detergent, but this hack rarely works for more than a few washes, it is fiddly to remove when I don't need it, and I'm always concerned that the plastic or sellotape will come loose, get sucked into the washing machine pipes where it will get stuck and cause a blockage or worse.
I've already dismissed the idea of using detergent tablets as I want to be able to tailor the amount of detergent I use per wash (minimise the detergent used given out water hardness). I've also had bad luck with pods (Liquid 'tablets') in the past. With low temperature/eco washes the plastic didn't always dissolve fully, leaving clothes covered in tiny plastic fragments (especially noticeable on black jeans).
Does anyone have a better way of making a washing machine powder drawer compatible with liquid detergents?