First I’ve heard of Epsom salt for ich.
Epsom salt is more for balance and digestion. Ich treatment is aquarium salt ie a small increase in salinity towards brackish although for ich raising the temperature to mid eighties often does the trick itself, after what at first looks like a flurry of dots.
You CAN use malachite green to treat scaleless fish but you have to use it at a much reduced dose. As little as 25-50 % of the stated dosage.
All that said, a healthy, happy fish can often fend off a mild dose of ich itself, so often best not to worry too soon if you see the odd white as spot.
I would not automatically think ich, I must treat it, IF yours was, and I also am not sure it is.