As the Buddha told, ordinary people see nicca where there is anicca, an anicca where there is nicca and that is best seen in the "Isn't everyone capable to perceive the good in the bad and the bad in the good?"
So like in many parts, simply following the advices of the teacher has more effect then to doubt around (like to be mature) before enter the school.
And again, it's not a teaching for householders but requires the beginn of outwardly training of one how is, or up on, to leave home (world, sense). So not for non-sekhas-nor-asekha.
A householder minds (even in robes but still a householder) defilements will use this "repelled/disgusted" just for nurishing hindrances and excuses to restrain from duties and good.
"repelled/disgusted" means turn away, reject home, house and go forth, again, and again. (even not into a robe carrying householder domain).
The beginners advice is nothing but an encouragement to leave home first, reject householder signs and means.
The Sutta shows also well that the usually teaching of dwelling in equanimity for householders is, again, not the teachers advice, not taught, since it's all about dangerous for a householder, here and here after. Consider this when thinking to approach another householder to householder coaching...: stay away from meditation teacher who teach nothing as meditation, actually not knowing path and it's means that condition samma-samadhi.
(note to entertain with assume for and back, trade and exchange, but for an exit out of the wheel)