بسم اللہ الرحمٰن الرحیم

:الجواب وباللہ التوفیق

Based on the words of your statement that: "Until I clean the dog's saliva from my body, my income is forbidden to me”, constitute an oath or a “qasam”. This will initiate a valid oath.

if you had said those words after having cleaned off the dog's saliva seven times, then the oath will not apply. But if you had not cleaned off the saliva from your body seven times, before taking the oath, then your oath stands valid which must be fulfilled. And until you cleanse the saliva as prescribed, your earnings will be forbidden for you. If you use your earnings, the oath will be broken. And in case of breaking the oath, it has to be expunged. 

The forms of  expiation are:

1. One slave be freed.

2. Or, Ten poor people are fed two full meals.

3. Or, each of the ten poor people should be given the amount of Sadaqat al-Fitr (one kilogram, 574 grams and 640 milligrams of wheat), or equivalent amount in monetary value. 

4. Or, each of the ten person should be clothed.

5. If none of the above is possible to afford,  then the person should fast for three consecutive days. 

{فَکَفَّارَتُہُ اِطْعَامُ عَشَرَۃِ مَسَاکِیْنَ مِنْ اَوْسَطِ مَا تُطْعِمُوْنَ اَہْلِیْکُمْ اَوْ کِسْوَتُہُمْ اَوْ تَحْرِیْرُ رَقَبَۃٍ فَمَنْ لَمْ یَجِدْ فَصِیَامُ ثَلَاثَۃِ اَیَّامٍ ذٰلِکَ کَفَّارَۃُ اَیْمَانِکُمْاِذَا حَلَفْتُمْ ۔ [المائدۃ: ۸۹] }

و کفارتہ تحریر رقبۃ او اطعام عشرہ مساکین او کسوتہم بما یستر عامۃ البدن۔۔۔۔۔ وان عجز عنہا وقت الاداء صام ثلٰثۃ ایام ولاء ( تنویر الابصار مع رد المحتار‘ مطلب کفارۃ الیمین ۳/۷۲۵‘ ۷۲۶‘ ط سعید )

فقط واللہ اعلم بالصواب