Cleaning Laser with Alcohol and Q-Tip

How bad is this if you have already done this?

depends on the lens.

some lenses have a coating which can either be dissolved in alcohol or scratched off with qtips.. If you've done it before, though, it can't harm too much to do it again.

At least get some canned air to blow away the little bits of cotton that the Q-tip leaves on there.

This is the method I use for cleaning all my lenses, and I've only come across ONE lens that got messed up because of it. It works perfectly on glass lenses and my aixiz acrylic lenses, but I had a 30mW romisen laser from DX that had an AR coated plastic lens and cleaning with the q-tip and alcohol ruined the lens, made the output very scattery and just no good.

In most cases, it will be fine