Howdydoodee,
I'm a bugger for gadgets, and I have just bought a new one. One which, having arrived from my friend A. Mazon, and tested, will save time. More than that, I have bought it in a colour my wife approves of, which is only fair as she paid for it.
Take a look at this,.....
https://www.amazon.co.uk/dp/B0B2JP7MW8?ref=ppx_yo2ov_dt_b_product_details&th=1The rotation is very strong for what it is - to the point that the 'stirrer' should be placed into the ink pot so it touches the bottom. I did realise this prior to inserting in the pot. (just placing the stirrer into the ink and letting it go halfway in will cause the ink to go over the top of the bottle. If the bottle is deeper than a single stirrer, just join another stirrer to the first stirrer to make it longer. Really good gadget and I can see this saving a lot of time and effort (ok, so mixing is relaxing, for me at least, but who doesn't like a gadget).