It’s makes sense to have a punting phone, the SP your contacting more than likely has one too, so there not mixing business with pleasure l.
Not for me though tried it, was never off the infernal thing so folk at work see me playing with 2 phones lol ,
I just use the privacy options on my phone, if it’s a one off they get blocked and deleted . If it’s a regular then they’ll go inside one of my mates contact details, again making use of the privacy options (mute) and all notifications turned off.
Or there’s Adultwork messenger