I changed the post title for brevity. You originally asked about head cleaning "in 2016". But I wanted to mention that head cleaning has no changed over time. Whether it was 1986 or 2016, dirt is dirt, grime is grime. Time takes a toll, and owns no calendar.
At most, in 1986, admittedly I'd have done a really crappy job of cleaning. But with quality VCRs being rarer now, I'd for sure take care of it. I'd not neglect it now.
16 hours is bad. Not just overkill, but bad. You'll long-term cause problems.
Comets (magnetic dropouts) is a confounding error. It's usually sign that the tapes are dropping debris on the heads, or that the tape is in poor shape. Or both. Sadly, in that case, yes, you'd need to clean it more often.
Magnetism is often talked about, but nothing concrete is proven. It's my belief that certain decks actually pull more debris from tapes, due to the magnetism of the head. So some here are apt to demagnetize their decks from time to time. The interval differs from user to user.
The static charge of the air in your home/office may be at fault too. It's still heater season in many places. That means lots of static in the air.
It will just take some time, patience, and a good process of elimination to find the problem. But hopefully this gives you a lead.
