It is - but you seem to get away with it a few times, before they ban you (according to others).
An option that avoids the ban is to:
bet £50 on >0.5 goals prematch
at another bookie, pre-match, bet a few quid on the 0-0, so the return on the win will be about £50.
At this point, whatever the result, you will lose nothing. However, you now have a completely risk-free £50 in-play bet that you can use on anything you like (but don't bet on the draw, to avoid the potential ban).
Do NOT bet on 0-0. Bet on No Goalscorer as this will still pay out if the only goal is an own goal.