The indoor house treatment I use is called Knockout ES Area Treatment. It is available in some hardware stores, sometimes even Lowe's and Home Depot. It is also available through multiple on line sources including Amazon. You might want to get enough to do two treatments 3 weeks apart. With the safety of either Comfortis or Trifexis it should be fine to redose at this time as long as it has been at least 2 weeks since any previous treatment. Be watching for tapeworms as they are spread by fleas. The videos about fleas and tapeworms might be useful.