Home depot sells small carbon filters you can use the plug right into outlets and are like 6 bucks they even give you extra filters!!! I worry about no smell I have a vortex 660 cfm fan with a 6 inch 440 cfm filter
Ona Gels work great for short period of time usually 3 weeks max for the regular jar size. You could use an air freshener that has a timer thing and sprays itself every 18 to 32 minutes. Walmart has them. That is what I used for my last grow. I am gonna get the Carbon Filter to save me money on the gels in the long run.
Ona Gels, or any of those Glade Air Freshener's that plug-in. I also had a friend who did the DIY Walmart Carbon Filter on here and had it setting for a couple of days before he finally got around to putting it in his venting system. You know what ... It cut down the smell a lot just like that. I think all of the material he got for his at one of those Dollar stores came out to like $4.00.
Good Luck in your situation and hope that you get the answer that you are looking for.