They are not ordinary Q-tips. The cotton swab (which looks like it is 10" long long so as to probe the deepest recesses of your nasal chamber) comes in a test tube package to which it will be returned before sending it off for analysis.
The cotton swab cannot be replaced by an ordinary Q-tip.
How you ever had a Covid-19 test?
Yes I have had a test and it was an ordinary Q-tip.