I am pretty well versed in the plant world, I personally know many vendors and have seen their operations. I also personally know or have seen the operations of many of the plant vendors' sources. So I will say this. I doubt you can be sure that your plants are "frog free" and not flipped because I have yet to meet any vendor ever who doesnt exchange and source plants from other vendors and doesnt flip some portion of their plants or have a greenhouse that may have lots of animals in it and likely a passing tree frog. And on that note, if you had a few frogs you would probably keep them around as they may eat pests. Anyone that pure probably went out of business already.
If you want something to be pure and make sure its safe, you have only one option, clean it and quarantine it yourself. For instance the bulk of the neoregelias that come into the hobby are mostly bought whole sale from a 1 particular supplier in Florida running a green house, very few people even attempt to propagate them at any scale themselves because its massive cheaper and less work to whole sale them from a guy who has great natural growing conditions and a mass scale green house. And others are often similar. The bulk of the orchids in the hobby are also purchased either directly or indirectly from 1 particular major south American supplier. In both cases these tropical sources are almost certainly going to have frogs in their greenhouses or farms. Sometimes a vendor doesnt even realize they are purchasing indirectly through one of these suppliers because they are getting something someone else flipped.
FWIW its food for thought.
If you have specific requirements you can PM me for a very small selection of plants that I have that are raised in in a specific condition. But if you are really curious you should ask very specific questions from any vendors and you should even be specific about the plants. For instance, various places will have a separate area for frog farming and plant farming, sometimes a separate room, and this separate room might have a much lower chance of frogs being in it than say someone who is a green house that doesnt raise frogs at all but would be unlikely to be able to stop occasional wild frogs from getting in. Sometimes a completely separate greenhouse exists from the frog raising operation, but then again they could still be pulling plants out of frog tanks. But you have to be very specific and very inquiring because there are alot of very different setups.
When you say dont broker I assume you mean flipping, the problem with flipping is that there is no specific definition. Obviously every single person has to originally source a plant from somewhere. Then the question becomes how much propagation do you wait for before you consider that plant flipped? Does it take generations? Time? Soil changes? What? And even if that specific plant was not flipped recently maybe another plant in the same growing area was. I personally have a Marcgravia el coca, it was one of the first 2 imported to the USA AFAIK. And I am still cutting off the same plant and the same pot to sell to people years later have not even changes the ABG. But in reality its a gen 1 plant.
I learned the hard way early on about all this and I now do my own cleaning and sterilization regiment before plants go into any show tanks I care about. And besides that I dont buy or care if someone advertises as frog free because personally i dont think it means much of anything at all other than they probably didnt pull that plant straight out of a frog tank. So I treat all plants from all sources the same. They get the full quarantine and treatment if they go into any vivarium I care about keeping clean.
