Brendon, you've made other posts that suggest you're trying to diversify & expand your biz, which is smart. If you're going to get serious about investing in the PHC side of things as a money maker, be prepared for it to take a long time to establish accounts.
You might consider starting low & slow. See if it works out for you & decide from there if it's worth continuing.
One idea might be to just get a little 2 gal. unit & offer a service of spraying Round-Up for your customers (driveways, planting beds, parking areas, etc.). I charge an average of $30 for this. It's a quick money maker & opens the door for more PHC queries.
A really organised person would set those particular profits aside for investing in more spray equip. & supplies, which I have not done.
PHC is a different creature. Having / being a knowledgeable salesperson is a must.