PCoJ invariably results in a custodial sentence. It is an "indictable only" offence (meaning it can only be dealt with in the Crown Court) and carries a maximum sentence of Life imprisonment.
The sentencing guidelines do allow for a lesser sentence if the underlying offence was not serious but even then, a prison sentence is all but inevitable.
Drivers have been known to attempt to avoid a speeding allegation by naming somebody they know not to have been driving:
https://www.theguardian.com/uk/2013/mar/11/chris-huhne-vicky-pryce
https://www.itv.com/news/anglia/story/2019-02-25/mp-convicted-of-perverting-the-course-of-justice/
Note that of those three, two were Members of parliament and one was an MP's ex-wife.
If it's any consolation to those who believe the sentence passed on Mr Snelling was harsh, although sentenced to six months' custody he will serve no more than six weeks.