Lots of good points made already.
Way back when, Bull Run had a very cheap social membership. Social members were welcome for that fee at all non-riding functions (except hunt ball for which everyone paid their way) and as a social member, you were welcome to come hunt and pay the capping fee. I don’t recall there was a limit on caps, as there was for guests, but such a membership is, I think, a good compromise for people who want to dip their toes in the water but for whatever reason don’t have the time to hunt often enough to justify full dues.
Junior members paid $25 a year, and ‘junior’ was defined as all the way through college.
We also tried, once, early 80s, a ‘free and open to anyone’ day and had gazillions of never-ever hunters turn out. Obviously we structured a number of extra hilltopper fields to accommodate the newcomers, and it was a pretty popular outing. But you do have to have a fixture that can accommodate large crowds and not every hunt does.
These days I mainly hunt out west, and I can tell you that pretty much every hunt, including Arapahoe, welcomes guests in whatever saddle, whatever attire they might have. The only requirement, generally, is a helmet and safe riding boots of some sort, but even the helmet is not a hangup if it’s cowboys/girls. Two positive effects from this- when the cowboys see just how much fun it is, and figure out that those people in the little bitty saddles and funny coats can really ride, word gets around about the ‘macho’ index and the sport is made even more welcome in the general area. Second thing- may of those cowboys/girls become pretty danged enamored of the sport. So once they throw in, they just naturally gravitate over time toward the correct attire, then the correct tack.
Here in huntless Utah, we do have an annual horse expo, and Back Country Horsemen has started a similar day but it’s limited to horse related non-profits, and the county, state and federal land management agencies. Likewise we have county and state fairs. If I had a subscription pack, I’d be setting up a booth at those gatherings, probably with a couple of friendly hounds (and if available irresistible pups) to meet and greet, and would exhibit the hounds with staff in full regalia as a part of the deal, maybe a couple of shows during the day. I would also (as Red Rock does) take my hounds to 4th of July parades, 4H and Pony Club meetings, anywhere that wants to see them. In other words, get out into the community instead of hoping the community will come to me.