John
I don't actually offer any self guided hunts but I do have an alternative.
For many years I've been doing hunts for pigs, goats, rabbits and foxes etc in Western Queensland at reduced rates if........
Hunters travel to the property in their own vehicle.
Supply their own camping gear.
Supply and cook their own meals.
I provide the hunting property, the guide, and the hunting vehicle. Charges depend on the number of hunters and days and what type of hunt they are looking for.
Regarding pigs and droughts, yes their numbers can be significantly reduced especially if the drought lasts for several years. During short term drought pigs will indeed survive by eating carcasses and travelling to better areas.
During long term, wide spread drought things are a little different. Here's why. The wild pig does very well feeding on dead animals so long as it is also eating some form of herbage. Without herbage in its diet it will gradually lose condition and if the drought lasts a long time and it is eating nothing but carcass, it will eventually die.
As you say, hunting pigs during drought conditions is usually much easier due to the fact that that both water and feed is scarse. Also with bare ground and little or no grass all animals are easier to spot over distance, and are easier to track as well. This works well for shooters and doggers wanting pigs for sale to the chillers. Trappers find it easier too as pigs will come for miles if the traps are baited correctly.
Then the property owner starts to notice the pigs more because they are easier to see and, worried by massive stock losses decides to reduce pig numbers by trapping, shooting, and baiting.
With our most recent drought, it was so wide spread that our Queensland pigs would have had to travel all the way to Tasmania to find a feed!

They'll bounce back though, they always have in the past.
Thesedays I do the serious pig hunting in Cape York in Queensland's top end because I don't have to worry about droughts up there. Pig numbers are always good if you have access to good hunting country in the top end.
I'll try and do a post soon on the big tuskers of cape york.
Cheers Alan