So, this is almost a 2 part video; firstly a reminder to myself that going back to some of the first kit in your den can get amazing results even if it is 'basic' compared to new purchases and secondly, my first time and review of Cella shaving soap.
I used to get neck irritation (not as severe), cold water shaving helped a lot.
Possibly revisit your beard mapping on your neck too, maybe straight down is not WTG for those trouble spots.