Based on my past studies, the NSAB is accurate, and most translations translate this text in a similar manner.

Having our spiritual garments washed or cleansed by the blood of Jesus is a theme throughout the book of the Revelation. Consider the following texts:

To Him who loves us and released us from our sins by His blood and He has made us to be a kingdom, priests to His God and Father—to Him be the glory and the dominion forever and ever. Amen. ~ Revelation 1:5b-6

But you have a few people in Sardis who have not soiled their garments; and they will walk with Me in white, for they are worthy. ~ Revelation 3:4

Then one of the elders answered, saying to me, “These who are clothed in the white robes, who are they, and where have they come from?” I said to him, “My lord, you know.” And he said to me, “These are the ones who come out of the great tribulation, and they have washed their robes and made them white in the blood of the Lamb. ~ Revelation 7:13-14

(“Behold, I am coming like a thief. Blessed is the one who stays awake and keeps his clothes, so that he will not walk about naked and men will not see his shame.”) ~ Revelation 16:15

Let us rejoice and be glad and give the glory to Him, for the marriage of the Lamb has come and His bride has made herself ready.” It was given to her to clothe herself in fine linen, bright and clean; for the fine linen is the righteous acts of the saints. ~ Revelation 19:7-8

Regardless of our eschatological preference as to the timing of the events contained in the book of the Revelation, one thing is crystal clear: throughout this blessed prophecy, those who are overcomers keep themselves clean by the power of the blood of the Lamb.

And they overcame him because of the blood of the Lamb and because of the word of their testimony, and they did not love their life even when faced with death. ~ Revelation 12:11

Overcoming victory comes by (1) the blood of lamb (2) our testimony of the lamb’s power, and (3) the willingness to lay down our lives for the lamb of God, Jesus Christ.

If you hold on to these three things, you can overcome anything!