Its an interesting concept, let me comment on it.
Specialized pills would just be prohibitively expensive.
Having a type of granular might be an idea, but it doesn't usually work to well for hydroponic type fertilizers. We are exploring this possibility, even if it might leave 1-2% insoluble in the final product, its pretty insignificant and may be worth convenience.
If dust is the actual main issue you are trying to combat, there are also many ways to avoid this. For indoor growers its probably the worst, since you might be in a small room with no air curculation. Few possible solutions
1) mix liquid concentrate outside or in a ventilated room, and bring it in
2) Using
Particulate Respirators masks
3) moving "slowly" to reduce dust
Also, the tea bag idea is interesting, we have thought of that before. It might be something to consider also, the problem is you have to have a set amount for tea bags (like 5g, 10g, 20g), and ever grower has a different size system. So you have set size tea bags, for different growers which is a problem. We could set it like "1 teabag = 1 gallon" but even then, at different stages of growth, and depending on your system variables, it would change even over the course of a few weeks.
You can also "make your own" teabag type things, just using a filter bag that you can customize for yourself. You could even do it in a ventilated area and make a few at a time, then bring it into your grow area.