Well that claim must be made or the whole underpinnings of the religion collapses, and there goes the safety net upon which the whole notion rests, since Christ's sacrifice was no full propitiation for sins.
Removing 282 words of Holy Scripture on a whim collapses the underpinnings of the faith; this is exactly what protestants do routinely; the Bible buffet: I'l take a big helping of this, but that over there that sounds crazy. i'll just pretend it ain't there.' Protestantism at its finest.
This is the inference the Protestants like making, both in discussing the role of works and discussing the purgatory. This inference is illogical, as is it precisely sacrifice of Christ and the mercy of God that make our works count for anything, and make purgation of sin possible.