שמות ג:כב
וְשָׁאֲלָ֨ה אִשָּׁ֤ה מִשְּׁכֶנְתָּהּ֙ וּמִגָּרַ֣ת בֵּיתָ֔הּ כְּלֵי־כֶ֛סֶף וּכְלֵ֥י זָהָ֖ב וּשְׂמָלֹ֑ת וְשַׂמְתֶּ֗ם עַל־בְּנֵיכֶם֙ וְעַל־ בְּנֹ֣תֵיכֶ֔ם וְנִצַּלְתֶּ֖ם אֶת־מִצְרָֽיִם:

I have always understood this phrase as it is translated by the KJV:

But every woman shall borrow of her neighbour, and of her that sojourneth in her house, jewels of silver, and jewels of gold, and raiment: and ye shall put them upon your sons, and upon your daughters; and ye shall spoil the Egyptians.

However, the Onkelos and other Targumim translate ותרוקנון ית מצרים, “ye shall ‘empty out’ Egypt”, and Rashi comments כתרגומו.

How does the root נצל come to mean “empty”?