I guess separation will fix the problem if it's permanent but if you hope to get them back together again it's no fix at all. The animosity will simply build with the separation as they lose any feelings of familiarity. Two days separation won't be enough for them to have totally lost their familiarity, but the less separation the better.
It's best to reintroduce them on the most "neutral ground
" that you have...so don't suddenly bring them together in the area they normally play, sleep or sit with you. Sometimes though reintroducing them at feeding time works well if they are both good eaters. So what we are doing here is using distraction...the hope is that they will be so intent on eating that they will forget the issue. Usually the feeding area is not what I would call neutral territory so it won't work so well if food
isn't a major part of their lives.
Have a water spray bottle so that if they look to be getting a bit fractious you can give them a spray to break their concentration...saves you taking the risk with your hands.
If you can get the Feliway soon then you can actually spray it on yourself (legs in particular) and also on your hands and wipe it all over each cat's coat. That will help. If the Feliway isn't working within 2-3 days I'd see your vet about Clomicalm or perhaps even Prozac as that works faster. I'm not suggesting anti-anxiety medication be used long term...just to re-establish their relationship.
Let me know how things go. Cheers, Peter