sleeping arduino wake on reset?

I have two UNO's wired in such a way as to allow one to RESET the other. I am doing this to allow one (the programmer) to be able to flash the second (the application). This part of the system is working great.

Now I'd like the programmer mcu to be able to wake the application mcu. I am already using my external interrupts for other tasks, so I cannot use these.

My thought process is that the application mcu would do whatever it needed to, for say 5 seconds, then go to sleep (powered down mode). Then, after an elapsed amount of time, the programmer would wake up the application mcu via the RESET pin.

I haven't tried it yet, but I am pretty confident the above will work. What I am not confident about is whether resetting the application mcu as part of normal course would somehow upset its functionality (e.g. it gets stuck in programming mode or has a set number of resets).

Has anyone attempted a similar mode of sleep operation?

Yes. It works well.

Alternatively you could use Pin Change interrupts.

When you don't write to EEPROM, and not to an SD memory card, and if any transmitting serial data can be terminated at any moment. Then you can reset it. The chp needs some time to start again and run the code in setup(), that means the external interrupts are not processed right away during a reset.

Thanks guys! This answered my question perfectly.