BIce, lot of opining has been done on the subject and the verdict is a clear definite maybe on the subject of break-in. Personally I have many other things I'd rather do than continuously swab down a barrel when I am at the range.
If you are a serious precision target shooter, it may possibly be worth it but if you are just a shooting hobbyist, I am skeptical it has a big impact or is worth the time for most. Of the firearms I have owned, I clean the barrel when I buy it and then clean the barrel when I am done shooting and the groups don't seem to change over the years.