@tsarstepan,
My Golly Tsar, thanks but what rigidity! Now, 98 was asking whether or not he might (in everyday conversation I'd suppose) use this contraction. I can only guess that in my 82 years I've heard the expression many score of times, and of course I associate with only the most refined of other humanoids
I'll concede in your favor however, that when I inquired of my Better Half, who is much smarter than I, she responded "not often, maybe 10 times"
But here's an interesting aside of pertinence (to maybe me only): It usually comes out as "otherth'n" typically in "otherth'n 'at" Because the "th" is so muted, 98's rendition seems entirely reasonable