If you DON'T shower daily how often should you really apply minox?

[earlysigner]

I work from home and am not physically active. I shower/bathe once every 3-4 days. Might sound gross but my girlfriend doesn't complain about the smell, I don't really sweat or anything.

I read about minox and it says you should shower daily while using it, I doubt washing it out of your hair matters much though. I know a lot of guys put it on at night and shower in the mornings, so its only on their head for ~8 hours.

If I'm not showering daily, should I really be reapplying daily? Or should I do it every 2 days? Once per shower? What's the proper way to go about this?