Yes, Demand CS can be applied using just about any type of sprayer including a hose end sprayer. The hose end sprayer needs to be able to be calibrated to 0.8 fl.oz. (24mL) of product per gallon of water.
The Chapin Slide Pump Sprayer would likely suit your needs well.The brass pump develops pressure up to 150 psi and allows you to reach targets over 30 feet away! Perfect for spraying the eaves of your home or any hard to reach areas. You can see a video of the sprayer in use here:
Demand CS is not a contact kill so once a fly contacts a treated area it could still get inside before it succombs to the insecticide, but that does mean that it is working. If the cluster flies have already made their way indoors they will be harder to control because they usually hide in a wall void or other inaccessible area and are only visible when the house warms up. If the cluster flies are in an attic or drop ceiling or other dark area, a fly light would do a great job controlling the population. Using small fly lights such as the FlyWeb Fly Light in the house would also help to catch the flies. Spray Talstar directly on baseboards, window frames, door frames, and places where utilities (pipes, wires, cables) enter in to the building and any other crack, crevice or gap where insects can enter. We also have a great guide here on "How to Get Rid of Cluster Flies" that might help.
Demand CS would be a great choice for general pest control for common insects found in and around the home. It can be applied every 90 days indoors and every 30 days outdoors. Termidor SC should ONLY be applied once every 6 months directly up against the structure on the exterior of foundation (1 ft up and 1 ft out). You should NOT apply Demand CS in the areas where you apply Termidor SC. Please refer to the product label prior to mixing and applying for complete usage instructions.
If Demand CS is leaving a visible residue, then we would recommend to use a lower dilution rate (0.2-0.4 oz. per gallon of water). Also, be sure you are only spraying as a spot and/or crack and crevice treatment. You could also consider going to an insecticide that is not micro-encapsulated, such as Talstar P. If you are removing all the reside, then you would need to reapply the insecticide.