Verse 2.55
ततः परमावश्यता इन्द्रियाणाम् ॥५५॥
tataḥ paramā-vaśyatā indriyāṇām ॥55॥
Pratyahara results in the absolute control of the sense organs
The effect of pratyahara is felt when the senses are mastered, and the mind
is ripe and avid for its spiritual quest.
When the senses have ceased to run after pleasures obtained from the
phenomenal world, they can be yoked to serve the soul
Sadhana pada instructs the sadhaka how to survey his own weaknesses in each domain - moral, physical, physiological and intellectual - and how to eliminate them, since they are not conducive to yogic discipline and spiritual Liberation.
Yama develops the art of living in society honestly;
Niyama, that of cleansing one's impurities.
Asana eliminates physical and mental perturbations,
pranayama maintains harmony and prevents dissipation of the flow of vital energy, making the mind a fit instrument for meditation.
Pratyahara sublimates both senses and mind.
Thus ends the external quest (bahiranga sadhana) . Now the sadhaka crosses the threshold of the internal quest (antaranga sadhana) of yoga.
Here ends the exposition on sadhana pada, the second chapter of Patanjali's Yoga Satras.
Indeed. Pratyahara can be practised by sadhakas. One can start even if there is very little control on senses. Pratyahara is complete withdrawl of senses from sense objects. Sadhaka refuses to give the food (any sensual stimulation) to mind and that naturally turns the attention inwards.
How long and easily this practice can be maintained successfully, depends on ripeness of mind. When repeated long/intense and dedicated perseverance and practice (of Pratyahara) is done, it inevitably shall result in absolute sense control.
PATANJALI YOGA SUTRAS