can you try putting something like coroplast or even just cardboard around the outside of the condo to keep all the hay inside? Then use a spare litterbox or tray under your hayrack to walk between where you store the hay and their condo (so you're not the one tracking it around). You can also put a mat/towel under the litterbox so they don't track hay everywhere.
I have the litterbox inside a larger plastic container (those shallow ones that can roll under the bed). That seems to contain most of their hay and mess. I also hang the hay rack directly over the litterbox so everything falls into it.