The OPTIM does not leave a residue, but almost all other disinfectants you have used in the past do. The smell is from the remaining organic materials and chemicals left to dry on the surfaces by disinfectants used before, along with the dust that settled on the moist surfaces. After applications, these dry residues are bound to the surfaces. Other disinfectants use fragrances to mask this residue. Most folks notice the smell of this old residue the first few weeks they use OPTIM.
OPTIM however does not leave a fragrance, or a residue, so you can smell if the surface is truly clean or not. Clean really doesn’t smell like alcohol, lemon or wintergreen, it doesn’t smell like anything at all.
In this case, you should wash with soap and water your work surfaces, then rinse and dry to remove the offending chemical residues. [Most studios have never done this]
From then on out, you should not notice any smell. It is good practice to wash and rinse surfaces that are often disinfected on a weekly basis to remove organic build up, regardless of the disinfectant product in use.