Yes I use a spray bottle.
And I do believe it is mostly because the paper towel keeps the moisture in more than keeping the light out.

Also I am growing indoors right now - which keeps the temps more stable than outside - but the past week it has cooled off and the house is not as warm - things are coming up a little slower (after about 3 days they seem to be 1/2" to 1" shorter than a few weeks ago)

PS I just build an 'ebb n flow' watering system - so far so good.