What can I use to clean my machine as a substitute for original cleaners? I have access to an automatic bean-to-cup Siemens coffee maker. It has periodic cleaning programs of its own and also its own cleaning materials.

Recently, we have difficulties finding these cleaning materials around. (Sure we can order abroad, but this time customs, etc. probably will be a mess and it will take too much time and effort.)

Does anybody have an idea what can I replace these with?

Cleaner: TZ80001
Descaler: TZ80002
In case you're still searching for alternative cleaning materials, I would recommend citric acid. You can easily find it pretty cheap on Amazon. Its the same concept as vinegar, but without the smell - vinegar will stink up your house and the machine, so I would recommend against it.