I might be wrong about this. Hope this does not distort the real meaning of Anatta and lead to confusion. If so please delete my reply.
I try to think of Anatta in terms of Anartha which is a word in several Indian languages which means No-Artha(No-Meaning) i.e. futile, useless. It makes it easy for me to understand as I have sanna of that Hindi word. Also, when someone says “Anarth ho gaya” in Hindi it means a disaster has happened. The samsaric process is basically a Anartha (disaster). For me it’s just another way of understanding the Trilakshna.
Of course the pali word Anatta is best to use but Anartha might make more sense to people from Indian background. Maybe Anartha probably originated from Pali language and Sanskrit speakers added the ‘r’ just like they added ‘r’ in karma, dharma etc. to make it sound more “posh”.