Yes, and I think the potential improvement seems quite small compared with DBS, but I imagine there’s not much risk involved, other than loss of £.
I put a couple of other projects/products on this thread - Vibration research - Research / Research discussion - Parkinson’s UK Forum (parkinsons.org.uk)
One is about a vibrating glove which ‘rewires the brain’ (maybe), and I already have bought a similar device which I use for a couple of hours each evening (while watching TV). It has won some awards in China and I was contacted by the designer after leaving a good review with some suggestions. Amazon reduced it to £20 so I bought a spare one. Seems not to have caught on.