Get proper company in to spray
If it is a really bad and well established infestation this is the only way to go. Some of the aerosol sprays you can buy from a vets are very powerful and will kill a lot of fleas but they have no residual action whereas a proper spray treatment carried out by a pest controller will remain active for at least a couple of weeks and will kill any newly hatched flea larvae which will help to break the life cycle. Even then you occasionally need two treatments with severe infestations. I get very few treatment failures but they do happen from time to time.
I seem to remember the treatment was ficam d with 5% bendiocarb
Well remembered. Its actually Ficam W you would use for a spray treatment and its about 80% bendiocarb. As a bonus for all you cat haters out there cats are eight times more sensitive to bendiocarb than other mammals and can on occasion be killed by it.
several versions that all contain the same active ingredient fiprinol at various price points.
I’ve heard lots of things to suggest that fiprinol is loosing favour as a flea control active ingredient. If you are going to buy any flea spray aerosols look for ones that contain a mixture of Permethrin and Tetramethrin, its the nuclear option. D-phenothrin is also pretty good.
If you do get a pro in to carry out a treatment expect to pay between £80 and £150 at todays prices. They should be prepared to provide a free follow up if the treatment isn’t 100% successful first time around.