Fun for the sake of fun makes the session memorable, but not necessarily the content...so says the person who recently completed some training on gamification.
Without knowing the content/topic of the SOP, it's difficult to think of ways to make the session both effective and enjoyable.
Can you create a "board game" where each block is a procedure step, but occasionally you have branches and they have to decide on what the correct next step is? They won't know if they're correct until they reach the end and either they're successful in creating the suitable output or they're not...in which case they need to go back to the beginning and try to determine where they went wrong.
If you have multiple boards, you can even turn it into a competition - the winning team has to help you clean up after the training is over. Everyone wants bragging rights at being the best, so sticking around after keeps them from becoming too arrogant.
Or, if you use something like Slido for an interactive learning system, you can have the group vote on which step is the correct one and they proceed as the majority votes.
