If someone wants to attain vraja-rasika bhakti, then can his mind get absorbed in the ordinary things? In material sense gratification? But if his mind is absorbed in material things, and he also desires vraja bhakti at the same time, then what will that mean?
It means that he does not really want this bhakti. If even the slightest greed to attain that prema is present, then detachment from all the worldly opulence will manifest. Spontaneously.
The unalloyed devotees are indifferent towards all worldly sense objects and opulence and remain one-pointed on attaining devotion in the mood of Vraja. They want nothing else. They do not even desire to attain liberation. They relinquish all of their desires and ambitions. And remaining unwavering in every way, only for the pleasure of the Supreme Lord, they engage in devotional practices in the wake of the gopis. Then alone it is possible to attain vraja-bhakti.