Is the perfect participle in deponent verbs active or passive in meaning?

Question

I recently read this interesting question in which Joonas provides a very instructive answer. It still left me, however, with some questions.

"Confitentes iterum ac tertio interrogavi supplicium minatus;" (Plin. Ep. 10.96)

[They were] confessing again, and on the third time I interrogated them having threatened punishment.

First, is my translation correct? I want to make sure we're on the same page.

Second, I notice that minatus is active in meaning, despite it being a perfect passive participle. This is consistent with Allen and Greenough §190a.

Are the perfect participles of deponent verbs active in meaning? I would think so, from the above evidence. However, I am confused by §190b from A&G.

190b. The perfect participle generally has an active sense, but in verbs otherwise deponent it is often passive: as, mercátus, bought; adeptus, gained (or having gained).

I assume that this point only holds true for deponent verbs, correct? (That the perfect participle generally has an active sense.) But then it goes on to say that for verbs otherwise deponent it is often passive. What does otherwise deponent mean? How can you tell whether the perfect participle will be active or passive in meaning, for a deponent verb?

Answer 1

190b. The perfect participle generally has an active sense, but in verbs otherwise deponent it is often passive: as, mercátus, bought; adeptus, gained (or having gained).

As I read it (with the help of some other paper grammars) this means: “Perfect participles of deponent verbs generally have an active sense. However, there are deponent verbs which follow all other rules, but have a perfect participle which can (also or only) have a passive meaning. Such verbs are an exception, but they are not uncommon.”

Good dictionaries will list those participles either as separate entries or as separate sections of the main entry. For instance, see mercatus at the end of mercor in L&S.