IF you lower from 1.026 to 1.022 it should be done over a long period of time. This lowering may have adverse effects on others in the tank, especially corals. I know most LFS run around 1.015 to1.020 as it helps reduce ich and other parasites, but this temporary until they are adopted.
As for garlic, they say it is a good appetite stimulate, but is NOT a cure for ich!
The only proven "cure" for ich is hypo salinity or copper Tx, all else is snake oil IMO/IME!
When I get new fish, while in QT, I feed them 10x more times than I do the DT fish. When they get paroled from QT to DT, I will still feed way heavy for a good week until they get settled in and have found their place. Of course heavy feeding comes with more water maintenance and water changes, but this is what has worked well for me.
Above everything else, a non-stressed fish is a happy/healthy fish and food helps they stay busy and happy!
If you cannot get them back out and into a hospital tank for a good 180 day Tx and QT, then you'll have to ride it out and hope for the best.
Best of luck to you!