I don't like percentages in this usage due to the following:
If I increase a value by 20%, and then decrease it by 20%, I do not get back to the same place.
However, if I increase a value by 5 dB, and then decrease it by 5 dB I do get back to the same place.
When dealing with a client who disliked dB, we compromised by saying "increase by the ratio 1.2:1, then decrease by the ratio 1.2:1", which gets us back to the same place.
(I prefer ratios greater than unity, inverting the ratio if needed.)