Technically the FAA only wants to see dual received logged for actual training, for example:

1) A Cert or Rating
2) Currency
3) Aircraft checkout
4) An area or route familiarization


This is not in the regs that I am aware of but has ben clarified by FAA legal opinions in which common-sense reality checks have been applied. Basically you could easily do one or two flights, log it as dual received and it would be really hard to argue against 3) or 4) above.

But if you log gobs of time and numerous flights without an obvious need for 1) or 2), it would be very difficult to make a case that you were engaged in 3) or 4).

Some people do this anyway, but an airline interviewer would likely be aware of the dubious legality of the time in question. A few flights here and there should not raise any flags, but I wouldn't base a large portion of your ME experience on "dual received" of this nature.