सत्य-शर्मा

Two kinds of impurity caused by sin

From the commentary

Sin causes two kinds of impurity; aihiki (related to this world) and amuṣmiki (related to the world beyond this world). The former causes loss of vyavahāra with Śiṣṭas, whereas the latter leads to naraka.

This is why when a sin of a person is known to others, its destruction requires much more prayaścitta. In the case of a hidden sin, due to the absence of aihiki impurity, the āmuṣmiki impurity goes away even with the lesser prāyaścittas like japa, homa, etc.

[द्विविधा ह्यशुद्धिः पापेन जन्यते ऐहिक्यामुष्मिकी चेति…., तयोरैहिकी शिष्टैः सह व्यवहारं वारयति । आमुष्मिकी तु नरकं प्रापयति।…, तत्र प्रकटपापेषु द्विविधाशुद्धिसद्भावात् तन्निवृत्तये प्रायश्चित्तबाहुल्यमपेक्षितम्…, रहस्ये त्वैहिकाशुद्ध्यभावादामुष्मिकमात्राशुद्धिः स्वल्पेनापि जपहोमादिना निवर्तते (अध्याय 12 रहस्यप्रायश्चित्तप्रकरण)]

A big prāyaścitta does not necessarily mean a difficult one

From the introduction to the commentary

In case someone thinks that a vrata/prāyaścitta which requires more effort is a great vrata, then people like the farmers and so forth would become the performers of great vratas.
This is why, a vrata which is praised by the Śāstra is great vrata.

[अनायासमहायासौ यद्यल्पत्वमहत्त्वयोः।
हेतुर्महाव्रतास्तर्हि भवेयुः कृषकादयः।
तस्माच्छास्त्रेण यस्योक्ता प्रशंसा तन्महाव्रतम्।]