Australia have clearly toned down their sledging since a ball-tampering scandal broke that involved Steve Smith, David Warner and Cameron Bancroft.
Du Plessis' South Africa beat India 2-1 in the series but Kohli emerged as the top run-getter with an aggregate of 286 from three Tests at an average of 47.66.
Du Plessis said, "He's an amazing player. We gave him the silent treatment and he still scored runs in South Africa, but we felt like it was not huge runs. He scored the one hundred there in Centurion when the wicket was slow.
"So every team will have what they think works for us, that was silent treatment."
Kohli, who is known for his aggressive behaviour, has been in imperious form throughout the year.
He notched up 593 runs against England in the five-match series and followed that up with three back-to-back hundreds against the West Indies in the One-day International series.
Faf du Plessis suggested Australian team to avoid confrontation with Virat Kohli and give him "silent treatment".