Those who have commented on purgatory not being found explicitly or implicitly in Scripture have spoken truly. What I would like to add to the discussion is from Revelation:
9 After this I beheld, and, lo, a great multitude, which no man could number, of all nations, and kindreds, and people, and tongues, stood before the throne, and before the Lamb, clothed with white robes, and palms in their hands;
10 And cried with a loud voice, saying, Salvation to our God which sitteth upon the throne, and unto the Lamb.
11 And all the angels stood round about the throne, and about the elders and the four beasts, and fell before the throne on their faces, and worshipped God,
12 Saying, Amen: Blessing, and glory, and wisdom, and thanksgiving, and honour, and power, and might, be unto our God for ever and ever. Amen.
13 And one of the elders answered, saying unto me, What are these which are arrayed in white robes? and whence came they?
14 And I said unto him, Sir, thou knowest. And he said to me, These are they which came out of great tribulation, and have washed their robes, and made them white in the blood of the Lamb.
15 Therefore are they before the throne of God, and serve him day and night in his temple: and he that sitteth on the throne shall dwell among them.
16 They shall hunger no more, neither thirst any more; neither shall the sun light on them, nor any heat.
17 For the Lamb which is in the midst of the throne shall feed them, and shall lead them unto living fountains of waters: and God shall wipe away all tears from their eyes.
Notice:
1. These people are before the holy throne of God and of the Lamb, where the 24 elders are and the four beasts. Here there is most certainly NOTHING unclean at all.
2. Those who are before the throne are from every tongue, tribe, nation, and people; more than can be numbered. And they are arrayed in white robes.
3. One of the elders gave the reason WHY they are before the throne. Brethren, fear God and do not add this his words. "These are they which came out of great tribulatio, and have washed their robes, and made them white in the blood of the Lamb."
4. They did not wash their robes in any supposed fires of purgatory as if some fire, heavenly or otherwise, removes the stain of original and actual sin. It is the Lamb of God who takes away the sin of the world and washed us from our sins in His own blood.
It is the blood of Jesus. This is the reason we are clean before an all holy God.