I have heard it both ways. I guess it ends up the same whether you use So for inhale and Hung for exhale or vice versa but it's weird. I used to laugh when I thought the words because So Hung sounds a bit like someone bragging about their genital endowment! LOL
A mantra is a mantra is a mantra. It took me a while to disconnect my breath from those syllables but once I did - what a relief. It's actually kind of irritating to have one's breath connected to anything repetitive - it's like a mindworm.
