In the thread about the word bleach, we were talking about how blankigaĵo could be interpreted as something that whitens or as something that is whitened.

In Esperanto, is it possible to form a word using the participles? For instance if the active participle were used, -anta, you would get blankigantaĵo, which to me seems like you could only interpret it as a thing that is whitening. Maybe in this case blankigontaĵo would be appropriate, because bleach in a bottle is something that will be whitening. Still seems a little weird though.

In contrast, the passive participles could be used to show that the object in question is on the receiving end of the action, so blankigitaĵo is something that has been bleached.

Let me know if this is proper in Esperanto, and if not, if my logic even makes sense!

Thanks!

Yes, you can use such words.
But often you can omit the middle suffixes and say "blankigaĵo" instead of "blankigotaĵo" or "blankigitaĵo" (when you whitens clothes), and bleach is "blankigilo" - the thing, which helps to whiten.
Another thing is if you whiten a wall.
The wall before whitening is blankigotaĵo, after it - blankigitaĵo and the paint is blankig(int)aĵo.

Excellent, thanks.