Last third of 7up with bit of ice in Hindu ritual (4)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

No, this isn’t about a brand of lemonade. 7 = reference to 7d TRAFALGAR, and “up” says we need to read it in reverse (upwards in a down clue), so the last third of it is [raglaf] ART ; then add the first letter (a bit) of I [ce]. I didn’t know this Hindu ritual but Wikipedia is helpful as usual.