According to ArbStättV, which is the German regulation for workplaces, the company needs to provide a washing opportunity, including soap. This is related to the sanitary rooms (read: bathroom), which need to be kept clean, and you need to be able to wash your hands and/or body.
However, there is nothing in there to justify even the existence of a tea kitchen, just stuff regulating that such a room for example doesn't need to have a window. So it's legit that the company does not provide washing up liquid, though it is quite weird, but also not uncommon.
My mother worked in the Arbeitsamt in a large German city for many years. They had kitchen rooms (Teeküche), which came with a sink and empty cupboards. There was no dishwasher, no kettle, no microwave, no plates, mugs or cutlery, or washing up liquid, no towels or even kitchen paper. No coffee machine either. Every office room of two or three people used to bring and keep their own dishes, coffee, tea and devices like a kettle. Some people stored their stuff in those kitchens and labelled it, but others locked it in their office because sometimes things would disappear. My mom and her office roommate also had their own sponge and dish washing liquid in their room. The only thing that the employer (in this case a government organization) supplied were vending machines for coffee and sweets in the hallways, but those were probably also meant for the customers (read unemployed people).
On the other hand, if someone decides that they want to start a fund to buy some stuff, like coffee or whatever, and they ask people to participate, that's just that. It's them asking. No-one can force you to contribute, just as they also cannot force you to chip in for coffee that you do not want to drink. You're very much entitled to say no.
Of course you should then have enough integrity to not actually use the stuff the other people bought from their own money.
Just tell them something along the lines of this.
I'm sorry, but I do not want to contribute money. I don't wash dishes here regularly, and I'm fine using the dish washer that the company provides. If you want to buy your own stuff that's great. Go ahead and don't worry, I'm not going to use it.